Solid catalysts



SOLID CATALYSTS 2 Sheets-Sheet l Filed Feb. 25, 1966 2S om w @di OmgCONVERS/OA/ W7 7o MADE/V.` JR. FRANK J. DZ/ERZAA/ows/f/ WALTER Feb. 6,1968 W. L. HADEN, JR., ETAL. SOLID CATALYSTS 2 Sheets-Sheet 2 Filed Feb.25, 1966 ab .bs GGQ omw CRACK/NG EFF/c/EA/cy (WT. @7a GAsoL//VE/ WT 70CoA/VERs/QN x m0)v /A/VE/VTORS WALTER L. HADE/V. JR. FRA/VK JDZ/ERZANOWS/(l ATTORNEY United States Patent 3,367,887 SOLID CATALYSTSWalter L. Haden, Jr., Metuchen, and Frank J. Dzierzanowski, Somerset,NJ. assignors, by mesne assignments, to Engelhard Minerals & `ChemicalsCorporation, Menlo Park, Edison, NJ., a corporation of DelawareContinuation-impart of applications Ser. No. 343,952, Feb. 11, 1964, andSer. No. 389,188, Aug. 12, 1964. This application Feb. 25, 1966, Ser.No. 530,064

Claims. (Cl. 252-455) ABSTRACT 0F THE DlSCLOSURE Solid zeoliticmolecular sieve catalysts are obtained by ion-exchanging andheat-treating a base material which is a composite of a highsilica-to-alumina form of hydrated sodium zeolite Y and raw kaolin clay.The base material contains 4 percent to 10 percent Na20 (on avolatile-free Weight basis) and the balance substantially A1203 and SiO2in a silica-to-alumina weight ratio within the range of 1.1-1.3 to 1.The catalysts obtained by ion-exchanging the base material have NaZOcontents less than about 2.5 percent and the same silica-to-aluminaratio as the base material from which they were obtained.

This application is a continuation-impart of our earlier filedapplications, Ser. No. 343,952, led Feb. 11, 1964, and now abandoned,and Ser. No. 389,188, tiled Aug. 12 1964.

This invention relates to catalysts and is especially directed tocatalysts adapted for use in the cracking of oil feedstocks to producegasoline.

An object of this invention is to provide a mechanically stablecomposite zeolitic solid base material capable of being converted tocatalysts of desired properties by ion-exchange and thermal activation.

A principal object of this invention is to produce novel high aluminazeolitic cracking catalysts characterized by exceptionally highcatalytic activity and selectivity to the production of gasoline,combined with outstanding stability in the presence of high temperaturesteam.

Another object is to produce relatively high bulk density zeoliticcracking catalysts which, because of their high density, enable the seallegs in certain catalyst cracking units to seal against higher pressuresthan catalysts of lower density and also permit the use of higher vaporvelocities through catalyst beds.

A specic object of the invention is provision of a highly active andselective zeolitic cracking catalyst that exhibits remarkable thermalstability in the presence of steam.

Another object is to produce mechanically strong cornposite zeoliticmolecular sieve cracking catalysts in which the sieve component isstabilized against the normally degrading etfect of steam during use orregeneration by an aluminum silicate component.

Further objects and features will be apparent :from the description ofthe invention which follows.

We have developed zeolitic molecular sieve composites that arecharacterized by remarkable mechanical strength and high density. Whenion-exchanged with suitable cations and activated, these compositespossess exceptionally high selectivity and activity in the cracking ofgas oil feeds to produce gasoline. The catalysts, which have a very highalumina content in comparison with commercial zeolitic mole-cular sievecatalysts, represent a marked advance in the art because of theirsuperior mechanical and thermal stability, high density and low cost.

ICC

Brieiiy stated, the composite catalyst-base mixture of this invention isin the form of mechanically strong particles containing microcrystallinezeolitic molecular sieve having substantially the X-ray `diffractionpattern of sodium zeolite Y, preferably a high silica-to-alumina molarratio form of sodium zeolite Y having a silica-to-alumina molar ratio ofat least 4, strongly interbonded with microcrystalline kaolin clay, thebase material containing, on a volatile free weight basis, from 4percent to 10 percent, preferably 5 percent to 7 percent Na20, and thebalance substantially A1203 and Si02 in a silica-to-alumina weight ratiowithin the range of 1.1-1.3 to 1. It is significant to note that thesilica-to-alumina molar ratio of the zeolitic constituent is much higherthan that of the composite base material, which has a silica-to-aluminamolar ratio of about 2.

Volatile free weight is determined by heating a material to essentiallyconstant `weight at 1800 F.

As shown in the illustrative examples, the catalyst-base material of theinvention can be obtained by hydrothermal treatment without dehydrationof preformed masses of sodium hydroxide solution, calcined amorphoushigh purity kaolin clays and high purity raw crystalline kaolin clay, ina manner such that the zeolitic molecular sieve is produced by reactionof the caustic principally with the calcined amorphous clays in situ inthe presence of the raw crystalline kaolin clay. The term kaolin clay asused herein encompasses clays, the predominating mineral constituent ofwhich can be kaolinite, dickite, nacrite or halloysite. Theaforementioned minerals are hydrous crystalline aluminum silicates ofthe formula A1203.2SlO2.XH2O

wherein x is usually 2. In producing catalysts, the following ionizablecompounds are representative of compounds which can be used to replacethe alkali metal of the catalyst-base material of the invention: saltsof ammonium, barium, calcium, magnesium, manganese, vanadium, chromium,cerium, cobalt, nickel, iron, zinc, aluminum, rare earths (lanthanum,praesodymium, neodymium and samarium), hydrogen and mixtures of theforegoing. The base material can also be processed to obtain compositeactive contact materials which contain elemental metals.

An outstanding feature of the composites is that they possess remarkablemechanical strength even before they are dehydrated by thermaltreatment. ln fact, the crystallized particles are much harder and moreresistant to attrition than particles of similar size and shape that arecomposed of high purity kaolin clay per se. The cornposite particles aresignificantly harder and more resistant to attrition than particles ofkaolin clay which have been hardened at temperaure levels used inprocessing the composites.

This invention is directed especially to a cracking catalyst which isobtained by ion-exchanging said composite base material with ammoniumions, whereby sodium ions are replaced lwith ammonium ions, andthermally activating the ion-exchanged particles. The cracking catalystis a high alumina content zeolitic composition analyzing (volatile freebasis) NagO in amount Within the range of 0.1 percent to 3 percent byweight and the balance substantially SiOZ and A1203 in a weight ratiowithin the range of 1.1 to 1.3 parts by weight SiOg per part by weightAl2O3. The preferred catalysts of the invention contain at least 0.4percent NaZO, since the production of catalysts with lower Na2O contentrequires large amounts of exchanging chemicals and long exchanging time.Catalysts of the invention containing more than 2.5 percent NaZO are notas steam stable as catalysts having a lower sodium content. For optimumselectivity, the higher range of sodium content is preferred; Foroptimum stability, the lower range of sodium content is preferred. Ourcatalyst may contain (and preferably does contain) more sodium than mostprior art zeolitic catalysts. Represent ative catalysts of the inventionhave the following chemical analyses, on a volatile free weight basis:

Percent NazO 0.4 to 2.5 F6203 A1203 tO SiOz 5 l to 55 TiOz and alkalineearth oxides Before activation, the catalyst of the invention ischaracterized by possessing an X-ray diffraction pattern containingpeaks characteristic of crystalline kaolin clay and peaks characteristicof ammonium zeolite Y, as described in U.S. Patent 3,l30,006 to Jule A.Rabo et al. (The excange of sodium ions in the composite-base materialwith ammonium ions may atfect slightly the apparent silica-toaluminaratio of the zeolite, as calculated from the X-ray diffraction pattern.)After thermal activation, whereby the composite is dehydrated andammonia is eliminated, the catalyst is characterized by possessing X-raydiffraction peaks substantially as follows.

d Spacing, A.: Line intensity i4 Very strong. 8.6 Medium. 7.3 Do.

5.6 Strong.

3.7 Medium.

From the brief description of the composition of the catalysts of thisinvention, it is apparent that our catalysts differ in composition fromprior art aluminosilicate gel and acid-activated clay catalysts. Withthe exception of certain acid-activated kaolin clay and mixed gel-claycracking catalysts, prior art catalysts usually contain a maximum ofabout 30 percent A1203. Our catalysts, however, differ in chemicalcomposition from the high alumina acid-activated kaolin clay and mixedgel-clay catalysts, which have a similar silica-to-alumina ratio sincesodium, which is an essential ingredient of our catalysts, is a poisonwhen present in the other high-alumina content catalysts. Further, ourhigh alumina content cataysts produce in many cases percent moreygasoline than the acid-activated clay catalysts and can operate withthis eciency at conversion levels not practical with acidactivated claycatalysts. In addition to possessing outstanding selectivity andactivity, catalysts of the invention are more stable to steam thancommercial cracking catalysts, including pelleted zeolitic molecularsieve catalysts. Our catalyst composites maintain their activity andselectivity when steamed under conditions which would destroy orsubstantially impair the pure zeolite. Further, our catalysts operatewith high activity and selectivity when steamed under conditions whichcause other zeolitic catalysts to lose their activity and selectivity.Another noteworthy feature of the catalysts is that they operate withthe desirable selectivity characteristics of the fresh catalyst evenwhen the catalytic activity decreases during service. Thus, ourcatalysts do not acquire the cracking characteristics of the matrix.This, of course, is not true of prior art composite molecular sievezeolite catalysts that contain catalytically active gel matrices Typicalphysical characteristics of our catalysts (activated) are as follows:

Bulk density, kg./l. 0.8 to 1.0 Surface area (B.E.T.), m.2/g. 75 to 150Hardness (cylindrical 4/8 mesh pelleted form)-4ball hardness, percenti.e., in excess of 200 111.2/ g Because of their high density, catalystsofthe invention enable seal legs in catalyst cracking units to sealagainst higher pressures and permit the use of higher vapor velocitiesthrough catalyst beds.

As mentioned, in producing our catalyst-base material the ingredients ofthe reaction mixture are selected to result in the crystallization ofcomposites containing crystalline kaolin clay, eg., kaolinite, and alsoa crystalline material which has the X-ray diffraction pattern of sodiumzeolite Y having a silica-to-alumina molar ratio of at least 3.5,preferably 4.0 to 4.8. Recommended is the use of 28 parts by weight raw(uncalcincd) kaolin clay, 171/2 parts by weight of sodium hydroxidesolution of 14 percent to 18 percent concentration, 2 parts by Weightmetakaolin (anhydrous amorphous kaolin clay calcined at a temperaturebelow which the exotherm takes place) and l2 parts by weight ofanhydrous amorphous kaolin clay that has been calcined at a temperaturesuch that the clay has undergone (passed through) the characteristicexotherm after dehydration is substantially completed. A chemicalbalance indicates that the crystallized product obtained from s-uchreaction mixture contains small amounts of one or more amorphousnonzeolitic components having a silica-to-alumina molar ratio less than2. The method for forming the particles will depend upon the size andthe shape of the catalyst particles since the size and shape of thereactant masses are retained substantially in the finished product. Forexample, to produce catalyst in the form of f-l/ 8 mesh (Tyler)cylindrical pellets for moving or xed bed catalytic operations, thereaction masses can be in the form of extruded pellets. Spray drying canbe used to form 1GO/325 mesh (Tyler) microspheres for uid bedoperations. The sodium hydroxide can be incorporated with the claysbefore the clays are shaped into particles or all or a part of thecaustic can be incorporated by soaking or impregnating preformedparticles. Small amounts of sodium silicate can be used in manufacturingthe catalyst-base material.

As a result of the hydrothermal treatment, without dehydration, asillustrated in the accompanying examples, some of the constituents ofthe particles react and form a material having substantially the X-raydiffraction pattern of sodium zeolite Y. The crystallization results ina marked hardening of the particles and a remarkably firm bond isestablished between the constituents in the particles. Thecrystallization of the zeolite in direct contact with the crystallinekaolin clay is essential to the development of particle hardnessadequate fOr usual catalyst use. In order to develop adequate hardness,the crystallized particles should contain at least about l5 percent byweight (dry weight basis) crystalline zeolite (as estimated by X-raydilraction). If desired, particles containing 50 percent zeolite (asestimated by X-ray) can be produced. When appreciably more than 50percent zeolite is present, the catalyst may not possess the desiredsteam stability. We prefer to formulate the reaction masses and carryout the reaction and crystallization under conditions such that theparticles contain 15 percent to 40 percent zeolite (as determined byX-ray diffraction). Composites that contain this quantity of zeolitehave a Na2O content within the range of 5 percent to 7 percent, on avolatile free weight basis. During activation and use, however, theamount of crystalline zeolite (as determined by X-ray) may be reducedsubstantially Without impairing the hardness or activity and selectivityof the catalyst. The crystallized particles are exchanged with ammoniumsalt to replace sodium ions with ammonium ions until the particlescontain the desired calculated sodium oxide content. At this point theparticles are hydrated. During subsequent thermal activation, which maybe before or during use, the ammonium content is eliminated by theformation and evolution of ammonia gas.

As mentioned, the Na20 content of the catalyst affects the activity andselectivity of the catalyst, especially the volume of gasoline producedat a given conversion level. Catalysts containing in excess of 1 percentNa2O nor- 6 powder diffraction patterns of products the criterion setforth in Table III of a publication by Donald C. Freeman, Jr. entitledElectrical Conductivity of Synthetic Crystalline Zeolites, Journal ofChemical Physics, vol.

mally result in more gasoline at a given conversion level 5 35, No. 3,September 1961. Table III in said publication than similar catalystscontaining less than 1 percent Na2O. correlates until cell dimensionwith SiO2/A12O3 ratio. The However, catalysts containing more than 2.6percent silica-to-alumina molar ratio of zeolite Y products was Na2O maynot possess the desired thermal stability. determined from the unit celldimensions derived from To activate the ion-exchanged masses and adjustthe X-ray diffraction patterns. activity to a desired level, the massescan be steamed 10 In estimating percentage of zeolite, a commercialsaniat about 1000 F. to about 1600 F. with 100 percent ple of highpurity sodium zeolite Y was used as a refsteam for two to four hours.This steaming also dehyerence. Percentage zeolite was estimated bycomparing drates the masses and hardens them further. the intensities ofcharacteristic peaks of samples with cor- The masses do not need to bedried before steaming. responding peaks of the sample of high purityzeolite. As mentioned, it is also within the scope of the invention Thefollowing kaolin clays were used in the preparato activate the catalystin a cracking unit. tion described in the examples.

Physical Characteristics Satintone #l Satintone #2 Min-Chem SpeeiaSpecific gravity 2. 63 2. 50 2, 5g Moisture, maximum wt. percent.. 1.01.0 1, 0 Wt. percent +325 mesh (wet screen). 0.5 0, 5 Q 5 Averageparticle size, microns 2. 0 4. 5 3, 5 pH 5- 8-6. 3 5. s-s. 3 3, 8 5. 0Typical chemical analysis (moisture-free weight basis Ignition loss at1,800 F., percent 0.5 0. 9 13, g Silica, percent 52- 3 52.1 45, 4Alumina, percent. 44. 6 44. 4 38, g Iron oxide 0.4 0.4 0.3 Titaniumdioxide, percent- 2.0 2.0 1.5 Calcination Treatment Calcmed AbobeCalcined Below Uncaicined Exotherm Exotherm Composition Amorphousamorphous Crysmuine (metakaolin) (kaolinite) While the highalumina-zeolitic catalyst of this in- Example I vention can be preparedby crystallizing a material having the X-ray diffraction pattern ofsodium zeolite Y by reaction of sodium hydroxide solution and calcinedkaolin clay in the presence of raw hydrated kaolin clay which, for themost part, does not enter into the reaction, comparable catalysts arenot obtained by binding pre-precipitated zeolite Y of suitablesilica-to-alumina ratio with raw kaolin clay. It has been found thatparticles obtained by the latter procedure are friable and do notpossess the mechanical strength required of catalysts. By way ofillustration, when the crystallization occurs in situ, pelleted extrudedparticles containing about percent zeolite (by X-ray) have a hardness ofabout 95 percent when tested by the hardness test described hereinafter.In contrast, when a similar amount of ionexchanged zeolite Y is mixedwith kaolinite and the mixture moistened, extruded and dried, relativelysoft particles having a hardness of only about 80 percent are obtained.Further, composites made by mixing preformed zeolite with kaolin clayare generally lower in alumina content than catalyst particles of thisinvention since zeolite Y has a substantially higher silica-to-aluminaratio than the overall silica-to-alumina ratio in our catalystparticles.

This invention and its features Will be understood more fully by thefollowing examples.

All X-ray diffraction results referred to in the examples were obtainedfrom random powder patterns using the K-alpha doublet of copper as thesource of X-radiation, a receiving slit width of 0.006, a Norelcospecimen holder having a sample area of 0.812 x 0.408, a scintillationcounter with pulse height analyzer, a scanning rate of 4 per minute, atime constant of 2 seconds, a scanning direction increasing from 2 to 90and a strip chart pen recorder. Specimens were equilibrated at C. and 40percent to 50 percent relative humidity for at least eighteen hoursprior to X-raying. Peak heights (counts per second, or c./s. andpositions were recorded on a strip chart. In view of the similaritybetween the diffraction patterns of zeolites X and Y, each of which hasa characteristic maximum of 6.2 20, zeolite X was distinguished fromzeolite Y by applying to X-ray In accordance with this invention aremarkable steam stable zeolite cracking catalyst possessing outstandingthermal stability and activity was prepared as follows.

3887 grams of Satintone #1 and 648 grams Satintone #2 were slowly mixedwith 4000 ml. of 16 percent NaOH solution (weight basis). The mixing wascarried out with a glass rod and Was continued until the mixture had anapparently uniform consistency. 9085 grams Min- Cheni Special wascharged to a double-screw pug mill. To the charge in the pug mill, themixture of Satintones and alkali solution was added. 500 ml. of 16percent NaOH solution was used to rinse the pan. that contained theslurry and, after being used to rinse the pan, the caustic was added tothe pug mill. To make the mix in the pug mill extrudable, another 350inl.. of 16 percent NaOH solution was added so that the total weight of16 percent NaOH solution was 5674 grams. The batch was pugged for tenminutes after the nal addition of caustic solution. The temperature ofthe charge in the pugger was 88 F. at the end of the pugging. Themixture was extruded under vacuum in a worm-type extruder having 0.17"diameter holes and the extrudate was cut into pellets about 0.25 long asthey issued from the extruder. The extrusion was made While the chargein the extruder was under a vacuum ranging from 28.0 to 28.8 Hg. Theextrudate temperature increased gradually from 90 F. at the beginning ofthe extrusion to 124 F. to 126 F. after 1/2 hour. Total extrusion timewas 34 minutes and the power used was 11.97 k.w.h./ton.

The freshly extruded pellets were placed in 1/2 gallon glass jars withthe pellets substantially lling the jars. The jars were sealed tightlyand maintained at room temperature of about 75 F. for 24 hours. The jarswith contents were then placed in an oven maintained at 200 F. and heldin the oven for a 24 hour period.

Without being washed or dried, 800 to 900 gram batches of the pelletswere exchanged at 180 F. i 10 F. with 1 N NH4NO3 solution by continuouspercolation of the aqueous solution through batches ot the pellets inexchange columns for about 48 hours. At the end of the exchanges, theNa2O content of the eluent were typically about 0.027 percent (asdetermined with a pH meter using a sodium-specific electrode). The pH ofthe efiiuents was about 7.3. The Na2O contents of the exchanged pelletsranged from 0.44 percent to 0.78 percent (based on the volatile freepellet weight).

Portions of the exchanged pellets were steam stabilized in a tubefurnace for four hours with 100 percent steam. In steaming one portion,steam at 1550 F. was used. The product was identified as Catalyst A.Another portion was steamed at 1575 F. to produce Catalyst B and anotherat 1600" F. to produce Catalyst C. To determine an upper limit ofthermal stability, steaming was carried out at l645 F. (Catalyst D.)After the steam treatment, the tnost significant physical properties ofeach catalyst were determined and catalytic properties were evaluated bythe CAT-D method (described hereinafter). The experimental claycatalysts, containing 0.44 percent to 0.78 percent Na2O and analyzingabout 45 percent A1203 with the balance being substantially all SiO2,were compared to a Grade A hardness commercial pelleted acid-activatedkaolin cracking catalyst of substantially the same silica-to-aluminaratio. The latter was obtained by pelletizing uncalcined kaolin claywith concentrated sulfuric acid, reacting the koalin clay with thesulfuric acid and, without washing out solubles, thermally desulfatingthe pellets under reducing conditions. Before testing the commercialhigh alumina content, acid-activated clay, it was calcined at l050 F. inair for four hours. The results are summarized in table form.

In carrying out the ball mill hardness tests (BMH), 4/5 mesh (Tyler)test samples, previously calcined in a muiiie furnace at 1050 F. andstored in desiccators, Were poured into tared 100 cc. graduatedcylinders to the 8O cc. mark, with gentle tapping to pack the particles.The weight of 80 cc. of the sample was determined. The 80 cc. portion ofthe sample was then placed into a stainless stee1 cylindrical containerwith four polished stainless steel ball bearings, each of /16 diameter.The container was closed tightly and it was then rotated about itslongitudinal axis on a roller arrangement at about 80 r.p.m. for onehour. After rotation had ceased, the particles in the container werescreened on a limiting sieve (a 6 mesh Tyler sieve) and the hardnesscalculated at the percentage of total sample Weight represented by thefraction of the material retained on the limiting sieve.

The method for measuring air jet hardness (AI H) is described in U.S.3,024,206 to James B. Duke, entitled, Method for Producing RoundedPlastic Masses.

The CAT-D test is a modification of the CAT-A method described inLaboratory Method for Determining the Activity of Cracking Catalysts, byI. Alexander and H. E. Shimp, page R537, National Petroleum News, Aug.2, 1944. In carrying out the CAT-D test, a heavy gas oil feedstock wasused and cracking was carried out at 900 F. with 10 percent steam and aliquid space rate of 1.0 (volume charge/volume of catalyst/hour) for afifteen minute operation period.

duced about 17 percent more gasoline and about half as much coke at asomewhat higher conversion level than the commercial high activity claycatalyst. These data therefore show that the catalyst of the inventionwas much more selective. Data for steaming the catalyst of thisinvention at 1575 F. and 1600 F. indicate that the selectivity andactivity of the catalyst was retained even after severe calcination,thus demonstrating the remarkable stability of the catalyst. Othercommercially available zcolite catalysts tend to lose activity at theselevels of steam treatment and, after being steamed at temperatures above1500 F. tend to have relatively poor selectivity correspondingsubstantially to that of conventional silica-alumina gel catalysts. Datain the ta'ble show that while some deactivation of the catalyst of theinvention occurred with 1645 F. steaming, the catalyst still producedmore gasoline than the clay catalyst at a somewhat lower conversionlevel.

Example II This example illustrates some of the effects of variation ofsodium oxide content on catalysts of the invention and demonstrates thesuperior selectivity of the higher sodium oxide content catalysts. Theexample also illustrates the superiority of catalysts of the inventionover commercial prior art zeolitic molecular sieve composites containinga silica-alumina gel matrix.

In a pilot plant operation using ingredients and proportionssubstantially as set forth in Example I, a pelleted catalyst-basematerial was crystallized containing 6.02 percent Naz() and the balancesubstantially SiO2 and A1203 in a weight ratio of 1.17 to 1. The pelletswere base-exchanged with 1 N ammonium nitrate solution in batchexchanges and portions of the pellets Withdrawn after a desired numberof exchanges were performed. In this way pellets were obtainedcontaining 0.82 percent, 1.28 percent, 1.79 percent, 2.26 percent, 2.78percent and 3.96 percent Na2O (on a volati-le free pellet weight basis).X-ray diffraction patterns of the pellets before the exchange treatmentindicated that they contained 20 percent sodium zeolite Y having asilica-to-alumina molar ratio of 4.28 to 1. In order to controlconversion level and to study the effect of steaming conditions onactivity and selectivity, portions of the exchanged pellets werecalcined at 1450o F. in one atmosphere of steam for four hours, andevaluated for catalytic properties. Other portions of the pellets weresteamed at 1500 F. for four hours, using one atmosphere steam pressure,and then evaluated. Still other portions of the exchanged pellets weresteamed at 1600 F. or at 1650 F. for four hours. Some samples wereresteamed for an additional four hours and re-evaluated. A competitivecommercial high activity zeolitic molecular sieve catalyst Was treatedin a similar manner.

It was found that the pelleted catalyst containing 3.96 percent Na2O hadexcellent activity and selectivity when PROPERTIES OF CATALYST DERIVEDFROM KAOLIN CLAY Steam Physical Properties Cracking Properties Cat. No.Treatment,

o F./t1r. B.D.1 Hardness AJ 11 3 Vul. Percent Wt. Per- Wt. Pcr- Gas Wt.Percent Kaolin Coke BMH 2 Gasoline cent Coke cent Gas Gravity ConversionFactor 1550/4 0. 927 97. 7 19. 3 52. 5 2. 3 14. 8 1. 48 60. 5 0.461575/4 0. 936 U6. 1 21. 3 50. 5 1.7 12. 4 1. 46 55.8 0. 43 1600/4 0. 04206. 7 25. 3 46. G 2. 0 12. l l. 39 52. 7 0. 56 1645/4 0. 964 (J5. 8 15.G 38. 6 1. 4 8.2 1. 28 41. 3 0. G9 Commercial Clay Cracking Cata1ystNone 0 T79 99.1 26. 3 O 4. 2 20. 4 1. 45 55. 4 1.08

1 Bulk density. 2 Ball Mill Hardness. 3 Air .I et Hardness.

The term kaolin coke factor used in presenting comparative catalyticdata, refers to a value obtained by comparing coke makel of theexperimental catalyst to that of a commercial kaolin catalyst at thesame conversion (extrapolated.)

The results in the table show that the catalyst of the invention afteractivation by steaming at 1550o F. prosteamed at 1350 F. When steamed at1450 F. for four hours, it was substantially inactive and resulted inonly 25 percent conversion of the feedstock, The catalyst containing2.78 percent Na2O was still active and highly selective at 1450 F.steaming for four hours (66 percent conversion) but with repeatedsteaming at 1450 F. the catalyst lost its activity.

A comparison of the activity of composite catalysts of the inventioncontaining 0.82 percent to 2.26 percent Na20 with the competitivezeolitic molecular sieve catalyst appears in FIGURE l. This figure showsthat catalysts of this invention maintained high activity levels inexcess of 40 percent Weight conversion when steamed under conditionswhich substantially deactivated the competitive zeolitic molecular sievecatalyst.

Cracking eiciencies of the catalysts were calculated by dividing theweight percentage gasoline by the weight percentage conversion andmultiplying by 100. The competitive catalyst had calculated crackingefliciencies of 71.2 percent and 70.6 percent when steamed at 1450 F.and 1550 F., respectively. These values represent weight percentageconversions to gasoline of 43 percent and 19 percent at steamingtemperatures of 1450 F. and 1550 F., respectively. As shown in FIGURE 2,catalysts of the invention containing 0.82 percent to 2.78 percent Na20had much higher calculated cracking eiciencies than the competitivecatalyst when activated at 1550 F. to 1650 F. For example, the catalystscontaining more than 1.78 percent Na20 had exceptionally high crackingefficiencies of 75 percent to 78 percent when activated at 1450 F. to1500 F. The catalysts containing 0.82 percent to 1.28 percent Na20 hadcracking eiciencies of 60 percent to 69 percent when steamed at 1500 F.However, data in FIG- URE 1 show that the latter catalysts operated atextremely high conversion levels (above 70 percent). Consequently, theoverall gasoline production was excellent although the ratio of gasolineto conversion was less than when conversion was at much lower levels.

We claim:

1. A base material for catalyst manufacture in the form of coherentparticles of a mixture of microcrystalline hydrated sodium zeolite Yhaving a silica-to-alumina ratio in excess of 4, as determined by X-raydiltraction, and -a major amount of raw hydrated kaolin clay, saidparticles having a density of at least 0.8 kg./l. when dehydratedthermally, and analyzing, on a volatile free weight basis, from 4percent to 10 percent Na20 and the balance substantially SiO2 and A1203in a weight ratio of 1.1 to y1.3 parts by weight Si03` per part byweight A1303.

2. The product of claim 1 which has a NaZO content within the range of 5percent to 7 percent.

f3. A composite material which is characterized by high catalyticactivity, selectivity and steam stability when heat activated andcontaining a mixture of raw hydrated kaolin clay and a zeolite componenthaving substantially the Xray diffraction pattern of ammonium zeolite Yhaving a silica-to-alumina molar ratio in excess of 4, and analyzing, ona volatile free weight basis, NazO in amount within the range of 0.1percent to 3 percent by weight and the balance substantially SiOz andA1203 in a weight ratio within the range of 1.1 to 1.3 parts by weightSiOZ per part by weight A1203.

4. The product of claim 3 in the form of mesh (Tyler) cylindricalpellets which have a hardness ot at least percent when tested by la ballmill attrition test for one hour and a density within the range of 0.8to 1.0 kg./l. after being heat activated.

`5. A cracking catalyst obt-ained by exchanging sodium ions in the basematerial of claim 1 with ammonium ions and heat activating saidexchanged base material, said catalyst having a density within the rangeof 0.18 to 1.0 kg./l. and being characterized by high catalyticactivity, selectivity and steam stability, said catalyst analyzing NaZOin amount within the range of 0.1 percent to 3 percent by weight and thebalance substantially Si02 and Al203 in a SiOZ to A1203 weight ratiowithin the range of 1.1 to 1.3 to 1, said catalyst being furthercharacterized by possessing X-ray dilraction peaks substantially asfollows:

d Spacing, A.: Line intensity 14 Very strong 8.6 Medium 5.6 Strong 3.7Medium.

6. The catalyst of claim 5 which has the following chemical analysis ona volatile free weight basis:

Percent Na20 0.4 to 2.5 F6203 A1303 43 to 46 Si02 51 to 55 TiO2 andalkaline earth oxides 2.0.

7. The catalyst of claim 5 which has a SiO2 to A1203 ratio of about 1.17to l.

8. The catalyst of claim 5 which is turther characterized by operatingat a CAT-D weight conversion level in excess of 40 percent when steamedwith 100 percent steam at temperatures within the range of 1350 F. tol550 F. for four hours.

9. The catalyst of claim 5 in the form of cylindrical pellets having ahardness in excess of 95 percent when tested by a ball mill attritiontest for one hour.

10. The catalyst of `claim 5 in which the yNaZO analysis is in excess of1 percent and does not exceed 2.5 percent.

References Cited UNITED STATES PATENTS 2,973,327 2/1961 Mitchell et al.252-449 3,119,659y -1/1964 Taggart et al. 23-112 3,205,037 9/1965 Maheret al. 23-112 3,244,643 4/ 1966 Schwartz 252--455 DANIEL E. WYMAN,Primary Examiner.

C. F. DEES, Assistant Examiner.

